1. Field of the Invention
This invention relates to electric motors and more particularly relates to a direct current (“DC”) hub motor.
2. Description of the Related Art
Electric vehicles offer hope for reduction of dependence on fossil fuels. However, electric vehicles have thus far been unpopular because of the limited range and the time required to recharge batteries. One of the major obstacles to increasing electrical vehicle performance is the efficiency of electric motors used to drive electric vehicles. While an electric motor may be smaller than a gas or diesel engine, large batteries are required that at least in part replace the weight of an engine.
A hub motor is a type of motor where the exterior of the motor rotates while the inner portion is fixed. A hub motor is advantageous because it can be attached to a wheel and can drive the wheel without an axel, drive shaft, transmission, or other components of a typical drive train. Elimination of a drive train greatly reduces the weight of a vehicle. While hub motors offers promise, typical hub motors suffer the same inefficiencies as typical electric motors. The inefficiencies are multiplied because two or more hub motors are required to power an electric vehicle. Typical hub motors are also heavy because they are made of metal. Typical hub motors also get hot due to eddy current losses and other inefficiencies.
What is needed is a new hub motor with increased efficiency that will overcome the problems associated with typical hub motors.